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UNITED STATES PATENT OFFICE.

ANDREV J. LAIRD, OI" MIDDLETOWIN, PENNSYLVANIA.

ARRANGEMENT' FOR OPERATING THE VALVES OF STEAM-ENGINES.

Specification of Letters Patent No. 30,329, dated October 9, 1860.

To all whom it may concern.'

Be it known that I, ANDREW JACKSON LAIRD, ot' Middletown, in the county of Dauphin and State of Pennsylvania, have invented a new and useful Device for Oper ating the Valve-Motion of Steam-Engines; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the saine, reterence being had to the accompanying draw ings, making a part of this specification, in which-,-

Figure l, is a perspective view of its application to the ordinary cylinder and steam chest, in common use, Fig. 2, a longitudinal elevation of the same, Fig. 3, illustrates the relative change ot1 the position of the sliding and vibrating-bar C, and rocker arm D, which latter device constitutes my improvement, vizz- By attaching one end of the said slidingbar C, on to the shackle-pin of the connect ing-rod B, which latter, is on the driving wheel A, at Z), in the usual manner, connected with the cross-head N, and piston L, the bar C, in its revolution with the connecting rod, has its other end free, which slides to and fro in the slotted rocker arm D, which latter moves on its pivot S, and is made to vibrate as illustrated by Fig. 3, adjusted to any desired stroke; the upper end of the rocker arm D, is connected with arm E, of the ordinary double V hook F, and compound crank-appliances for reversing the valve motion as shown, which are well known to every machinist, and together with the steam chest, cylinder &c. need no description in this place, as those are no part of my invention, simply the said sliding and vibrating arm C, and rocker arm D, which as shown, is readily understood.

This simple device is easily applied, either to stationary or locomotive engines, and is calculated to supersede the use of the numerous eccentries now employed, both Jfor forward and backward valve-gearing, with their complicated cranks and rods, so difficult to adjust and expensive, by the time and labor usually required in their adaptation to give the desired valvennotion. IVhile, by employing the bar C, acting in unison with the connecting rod, piston and driving wheel, the necessary adjustment of the rocker-arm D, is easily made and the desired stroke of the valve-rod and valves obtained, with the greatest exactness; so that, this device simple as it is, contains all -the requisite qualities of the complicated ma chinery and expensive adjustment of the several eccentrics employed to produce the forward, and backward motion, (and cut olf in some engines, also.)

I do not claim the double V hook and shifting rod, and crank-levers combined with my rocker-arm and valve rod.

lVhat I claim as my invention and desire to secure by Letters Patent is- The vibrating and sliding-bar C, in combination with the rocker-arm D, substan tially as set forth, for operating the valvemotion of steam engines.

S. G. MUssER, JACOB STAUFFER. 

